Satan was made evil when God hid from him and denied responsibility for setting him on the dark path

God hides.  People think they see what he does but they do not report seeing him.

The idea of the hiding God is necessary to explain how the cleverest and most powerful angel in Heaven, Lucifer, turned away from God. Such a being could never be stupid enough to throw all the heavenly happiness away unless he was at an epistemic distance from God. In other words, Satan essentially did not have complete knowledge or union with God so he was able to doubt that God was the only good thing for him. If Satan wanted to have his own way, that would indicate that he was bothered by a lack of something. That is what a want is. You are bothered by a lack and want to fulfil the lack. If being with God is perfect happiness you cannot have a lack. You therefore will not sin. If Satan had a lack then he was not with God perfectly for he did not know him perfectly. That God hid a bit from Satan he is ultimately to blame for the trouble Satan caused. God saw it coming - he didn't even need to look into the future for that one! And God simply didn't care.